ANSI 挖土的安全要求 Safety Requirements For Excavations.doc

SAFETY REQUIREMENTS FOR EXCAVATIONS 01. Scope: a. Excavations shall conform to all other applicable requirements of this standard, as well as the following provisions. Nothing in this standard shall be construed to prohibit better or otherwise safer conditions than specified herein. b. This section applies to all open excavations made in the earths surface. Excavations shall include trenches. 02. Definitions. For other definitions of terms used in this section, see sub-section 010 of this standard.. a. Accepted Engineering Practices are those requirements which are compatible with standards required by a licensed professional engineer. b. Aluminum Hydraulic Shoring is a pre-engineered shoring system comprised of aluminum hydraulic cylinders (cross braces) used in conjunction with vertical rails (uprights) or horizontal rails (wales). Such a system is designed specifically to support the sidewalls of an excavation and prevent cave-ins. See Figure 02-A. c. Bell Bottom Pier Hole is a type of shaft or footing excavation, the bottom of which is made larger than the cross section above to form a belled shape. d. Benching (Benching System) is a method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical or near vertical surfaces between levels. e. Cave-In is the separation of a mass of soil or rock material from the side of an excavation, or the loss of soil from under a trench shield or support system, and its sudden movement into the excavation, either by falling or sliding, in sufficient quantity so that it could entrap, bury, or other wise injure and immobilize a person. f. Cemented Soil is a soil in which the particles are held together by a chemical agent, such as calcium carbonate, such that a hand size sample cannot be crushed into powder or individual soil particles by finger pressure. g. Cohesive Soil is clay (fine grained soil), or soil wit